Improved quality of life in head and neck cancer patients treated with modern arc radiotherapy techniques - A prospective longitudinal analysis.

Purpose: The present longitudinal study aimed to evaluate the potential impact of modern radiotherapy (RT) techniques on quality of life (QOL) in patients with head and neck (HNC) cancer. Materials and methods: In this single-center prospective study, participants were asked to complete QOL questionnaires that included the EORTC QLQ-C30, QLQ-H&N 35 and utility score by time trade-off (TTO) at three time points (2 weeks, 3 months and 6 months) after completion of RT. All patients were treated by modern RT techniques [volumetric modulated arc therapy (VMAT) or helical tomotherapy (HT)]. Patients who developed recurrence or died before the 6-month follow-up were excluded. Linear mixed models with random intercepts for participants and restricted maximum likelihood estimates were used to assess the effect of our study variables (age, sex, primary site, cancer stage, treatment, radiation dose and radiation method). Overall changes in QOL, utility scores and symptom burdens at different time points were tested using paired t tests. Results: A total of 45 patients were recruited from 2022 to 2023. Those who completed the surveys at 2 weeks with at least 1 follow-up (30 patients, 67%) were enrolled in the final analysis. The majority of these 30 patients were men (76.7%), had oral cancer (40%), had stage III or IV disease (60%), received surgical intervention (63%) and were treated with chemoradiation (80%). A curative total dose of 66 to 70 Gy was delivered to 23 (76.7%) patients, half of whom received HT. Patients who received chemotherapy had significantly lower global QoL scales (mean difference, 27.94; 95% CI, 9.33-46.55; p=0.005). Global QOL, physical function, symptoms of sticky saliva, cough, feelings of illness and weight loss improved significantly between 2 weeks and 3 months. There was no significant difference between 3 and 6 months. Interestingly, improvements in social function, social contact, pain and nutrition reached significance at 6 months. Subgroup analysis revealed greater pain relief over time for patients who underwent HT (p=0.030). Moreover, patients who participated in swallowing rehabilitation programs had a greater decrease in nausea and vomiting (p=0.036). Conclusion: HNC patients treated with modern RT techniques experience improved QOL and physical function over time. The most significant improvement occurs between 2 weeks and 3 months, after which the improvement plateaus. However, social function, social contact, pain and nutrition may require longer recovery intervals after treatment. HT with daily image guidance could provide a therapeutic opportunity for improving pain relief in patients with HNC.

Effect of replanning boost radiotherapy plan in locally advanced unresectable middle to lower thoracic esophageal cancer.

Thoracic bulky esophageal cancer shrinks during radiotherapy, changing the location and shape of the surrounding heart and lungs. The current study aimed to explore how replanning by volumetric-modulated arc radiotherapy (VMAT) and three-dimensional conformal radiotherapy (3DCRT) influences the target coverage and dose to organs at risk in locally advanced unresectable middle to lower thoracic esophageal cancer. We retrospectively collected CT simulation images of initial and boost radiotherapy plans for locally advanced unresectable thoracic esophageal cancer in 17 consecutive patients. First, we created boost plans of 20 Gy using 3DCRT and VMAT on the initially acquired CT images. Second, we replicated the process on CT images acquired after 20-40 Gy of radiotherapy. We then compared non-replanned boost radiotherapy plans with replanned boost plans. Replanned radiotherapy delivered more conformal doses to the target and reduced heart and lung doses. VMAT reduced more irradiated mean doses to the heart than 3DCRT in the case of replanning (1.7 and 1.1 Gy, p < 0.001). Replanning to accommodate tumor shrinkage during radiotherapy effectively lowers the irradiated doses to the heart and lungs in patients with locally advanced unresectable middle to lower thoracic esophageal cancer, especially those treated with VMAT.

Multidirectional Filamented Light Biofabrication Creates Aligned and Contractile Cardiac Tissues.

Biofabricating 3D cardiac tissues that mimic the native myocardial tissue is a pivotal challenge in tissue engineering. In this study, we fabricate 3D cardiac tissues with controlled, multidirectional cellular alignment and directed or twisting contractility. We show that multidirectional filamented light can be used to biofabricate high-density (up to 60 × 106 cells mL-1) tissues, with directed uniaxial contractility (3.8x) and improved cell-to-cell connectivity (1.6x gap junction expression). Furthermore, by using multidirectional light projection, we can partially overcome cell-induced light attenuation, and fabricate larger tissues with multidirectional cellular alignment. For example, we fabricate a tri-layered myocardium-like tissue and a bi-layered tissue with torsional contractility. The approach provides a new strategy to rapidly fabricate aligned cardiac tissues relevant to regenerative medicine and biohybrid robotics.

Development of silk microfiber-reinforced bioink for muscle tissue engineering and in situ printing by a handheld 3D printer.

Volumetric muscle loss (VML) presents a significant challenge in tissue engineering due to the irreparable nature of extensive muscle injuries. In this study, we propose a novel approach for VML treatment using a bioink composed of silk microfiber-reinforced silk fibroin (SF) hydrogel. The engineered scaffolds are predesigned to provide structural support and fiber alignment to promote tissue regeneration in situ. We also validated our custom-made handheld 3D printer performance and showcased its potential applications for in situ printing using robotics. The fiber contents of SF and gelatin ink were varied from 1 to 5 %. Silk fibroin microfibers reinforced ink offered increased viscosity of the gel, which enhanced the shape fidelity and mechanical strength of the bulk scaffold. The fiber-reinforced bioink also demonstrated better cell-biomaterial interaction upon printing. The handheld 3D printer enabled the precise and on-demand fabrication of scaffolds directly at the defect site, for personalized and minimally invasive treatment. This innovative approach holds promise for addressing the challenges associated with VML treatment and advancing the field of regenerative medicine.

Volumetric measurement to evaluate treatment response to induction chemotherapy on MRI outperformed RECIST guideline in outcome prediction in advanced nasopharyngeal carcinoma.

BACKGROUND: Treatment response evaluated by tumour size change is an important indicator for outcome prediction. Advanced nasopharyngeal carcinoma (adNPC) grows irregularly, and so the unidimensional measurement may not be accurately applied to adNPC for outcome prediction. This study aimed to evaluate values of unidimensional and volumetric measurements for treatment response to induction chemotherapy (IC) for outcome prediction in adNPC and compared the values with that of RECIST 1.1 guideline. MATERIALS AND METHODS: Pre-treatment and post-IC magnetic resonance images (MRIs) from 124 patients with stage III-IVA NPC were retrospectively reviewed. Sums of the maximum unidimensional diameters (D) and volumes of the targeted tumours (primary tumour and two largest metastatic lymph nodes) on the pre- (Dpre and Vpre) and post-IC MRIs (Dpost-IC and Vpost-IC) and percentage changes in D (Δ D%) and V (ΔV%) between two scans were calculated and correlated with disease-free survival (DFS), locoregional recurrence-free survival (LRRFS), and distant metastases-free survival (DMFS) using Cox regression analysis. Area under the curves (AUCs) of independent measurements and RECIST groups (RECIST response and non-response groups) for predicting disease recurrence, locoregional recurrence, and distant metastases, respectively, were calculated and compared using the DeLong test. RESULTS: Univariable analysis showed correlations between high Dpost-IC with poor DFS and DMFS (P < 0.05), but not with LRRFS (P = 0.07); high Vpost-IC and low ΔV% (less decrease in volume on post-IC) with poor DFS, LRRFS, and DMFS (P < 0.05); and no correlations between Dpre, ΔD%, and Vpre and the outcomes (P > 0.05). Multivariable analysis showed that ΔV% was the only independent measurement for outcomes (P < 0.05). Compared with RECIST groups, ΔV% of 47.9% (median value) showed a higher AUC for disease recurrence (0.682 versus 0.526, P < 0.01) and for locoregional recurrence (0.782 versus 0.585, P < 0.01), but not for distant metastases (0.593 versus 0.518, P = 0.26). CONCLUSIONS: Volumetric measurement to evaluate treatment response to IC outperformed unidimensional measurement and RECIST guideline in outcome prediction in adNPC.

Replacing manual planning with automatic iterative planning for locally advanced rectal cancer VMAT treatment.

PURPOSE: To develop and implement a fully automatic iterative planning (AIP) system in the clinical practice, generating volumetric-modulated arc therapy plans combined with simultaneous integrated boost technique VMAT (SIB-VMAT) for locally advanced rectal cancer (LARC) patients. METHOD: The designed AIP system aimed to automate the entire planning process through a web-based service, including auxiliary structure generation, plan creation, field configuration, plan optimization, dose calculation, and plan assessment. The system was implemented based on the Eclipse scripting application programming interface and an efficient iterative optimization algorithm was proposed to reduce the required iterations in the optimization process. To verify the performance of the implemented AIP system, we retrospectively selected a total of 106 patients and performed dosimetric comparisons between the automatic plans (APs) and the manual plans (MPs), in terms of dose-volume histogram (DVH) metrics, homogeneity index (HI), and conformity index (CI) for different volumes of interest. RESULT: The AIP system has successfully created 106 APs within clinically acceptable timeframes. The average planning time per case was 36.8 ± 6.5 min, with an average iteration number of 6.8 (±1.1) in plan optimization. Compared to MPs, APs exhibited better performance in the planning target volume conformity and hotspot control ( p < 0.001 $p < 0.001$ ). The organs at risk (OARs) sparing was significantly improved in APs, with mean dose reductions in the femoral heads, the bone marrow, and the SmallBowel-Avoid of 0.53 Gy, 1.18 Gy, and 1.00 Gy, respectively ( p < 0.001 $p < 0.001$ ). Slight improvement was also observed in the urinary bladder V 40 Gy ${{V}_{40{\mathrm{\ Gy}}}}$ and the small bowel D 2 cc ( p < 0.001 ) ${{D}_{2{\mathrm{\ cc}}}}\ (p < 0.001)$ . Additionally, quality variation between plans from different planners was observed in DVH metrics while the APs represented better plan quality consistency. CONCLUSION: An AIP system has been implemented and integrated into the clinical treatment planning workflow. The AIP-generated SIB-VMAT plans for LARC have demonstrated superior plan quality and consistency compared with the manual counterparts. In the meantime, the planning time has been reduced by the AIP approach. Based on the reported results, the implemented AIP framework has been proven to improve plan quality and planning efficiency, liberating planners from the laborious parameter-tuning in the optimization phase.

Anatomical and dosimetric variations during volumetric modulated arc therapy in patients with locally advanced nasopharyngeal carcinoma after induction therapy: Implications for adaptive radiation therapy.

Purpose: To investigate anatomical and dosimetric changes during volumetric modulated arc therapy (VMAT) in patients with locally advanced nasopharyngeal carcinoma (LA-NPC) after induction therapy (IT) and explore characteristics of patients with notable variations. Materials and methods: From July 2021 to June 2023, 60 LA-NPC patients undergoing VMAT after IT were retrospectively recruited. Adaptive computed tomography (aCT), reconstructed from weekly cone-beam computed tomography(CBCT), facilitates recontouring and planning transplantation. Volume, dice similarity coefficients, and dose to target volumes and organs at risk(OARs) on planning CT(pCT) and aCT were compared to identify changing patterns. Multivariate logistic regression was used to investigate risk factors. Results: The volumes of PGTVnasopharynx (PGTVp), PGTVnode (PGTVn), ipsilateral and contralateral parotid glands decreased during VMAT, with reductions of 2.25 %, 6.98 %, 20.09 % and 18.00 %, respectively, at 30 fractions from baseline (P < 0.001). After 25 fractions, D99 and D95 of PGTVn decreased by 7.94 % and 4.18 % from baseline, respectively, while the Dmean of ipsilateral and contralateral parotid glands increased by 7.80 % and 6.50 %, marking the peak rates of dosimetric variations (P < 0.001). The dosimetric fluctuations in PGTVp, the brainstem, and the spinal cord remained within acceptable limits. Furthermore, an initial BMI ≥ 23.5 kg/m2 and not-achieving objective response (OR) after IT were regarded as risk factors for a remarkable PGTVn dose reduction in the later stages of VMAT. Conclusions: Replanning for post-IT LA-NPC patients appears reasonable at 25F during VMAT. Patients with an initial BMI ≥ 23.5 kg/m2 and not-achieving OR after IT should be considered for adaptive radiation therapy to stabilize the delivered dose.

Surgical Management of a Large Endodontic Periapical Lesion With Bone Putty and Platelet-Rich Fibrin: A Case Report With a Two-Year Volumetric Follow-Up.

The present case report evaluates the surgical management of a large periapical lesion with palatal perforation using platelet-rich fibrin (PRF) and bone putty material, with a two-year follow-up. A 15-year-old male presented with persistent swelling and pain in the right maxillary anterior region, having a history of trauma and recurrent swelling. Cone beam computed tomography (CBCT) imaging revealed a large periapical lesion extending from teeth #11 to #15 with a palatal breach. Initial non-surgical root canal treatment (RCT) failed due to persistent exudation from teeth #11, #12, and #13. This led to the decision for periradicular surgery involving cystic lesion enucleation, apicoectomy, retrofill with mineral trioxide aggregate (MTA), and placement of bone putty and PRF. Follow-up assessments, including volumetric analysis with ITK-SNAP software (www.itksnap.org), showed a 97% reduction in lesion volume, from 4055 to 132 cubic millimeters. The palatal perforation was successfully repaired, with no clinical symptoms reported. Substantial reduction in lesion size and successful repair of the perforation highlight the potential of this approach in complex surgical endodontic cases.

Treatment-Refractory Scleredema Diabeticorum Managed With Re-irradiation Using Volumetric Modulated Arc Therapy.

Scleredema diabeticorum is a rare connective tissue complication of diabetes, most typically observed in adults with longstanding type 2 diabetes. Patients develop reticular dermis thickening with a peau d'orange appearance at the upper back and neck that occasionally extends over the deltoids and lower back. While considered a benign disorder, it may signify more significant diabetes and can be functionally and cosmetically impairing with insidious onset, few to no effective treatments, and low spontaneous remission potential. Treatment options are limited; however, radiation therapy has shown clinical benefit in severe cases. Common treatment utilizes 20-24 Gy in 10-12 fractions with retreatment sometimes required for adequate symptom control. Here, we present a case of extensive, treatment-refractory diabetic scleredema status post six separate prior treatments with electron radiotherapy with clinical progression of disease, including involvement of anterior neck limiting jaw and neck range of motion. Volumetric modulated arc therapy (VMAT) was utilized to cover all areas of extensive disease and to treat deeper tissues, which we postulated may decrease skin and underlying tissue tightness and provide clinically meaningful improvements in range of motion. A 57-year-old female with longstanding type 1 diabetes and a six-year history of biopsy-confirmed scleredema presented with treatment-refractory disease in 2022 of the upper back, bilateral upper arms, and neck. Her disease distribution included 270 degrees around her neck, making electron therapy unviable. She had previously undergone multiple treatments, including six separate electron radiotherapy treatment courses to her back, shoulders, and posterior neck between 2016 and 2020 (ranging from 12 Gy in 6 fractions to 24 Gy in 12 fractions for each course), psoralen UV-A therapy, physiotherapy, methotrexate, and percussive therapy. To address the disease extending anteriorly around her neck and below her jaw, as well as the posterior involvement of her shoulders, back, and neck, a more extensive VMAT re-irradiation plan was developed. The plan successfully delivered 20 Gy in 10 fractions to areas of clinically evident disease. Toxicity was evaluated using the Common Terminology Criteria for Adverse Events (CTCAE) scoring system at the time of treatment and at the three-month follow-up. Functional improvement, patient satisfaction, skin texture, and induration were assessed during treatment and at her follow-up visit. Following VMAT re-irradiation, the patient denied scorable toxicity and noted the return of mobility in her neck and jaw. We concluded that VMAT-based re-irradiation is a safe and effective option for patients with treatment-refractory scleredema diabeticorum that is non-responsive or not amenable to electron therapy.

Differential evaluation of neuromuscular injuries to understand re-innervation at the neuromuscular junction.

Peripheral nerve-crush injury is a well-established model of neuromuscular junction (NMJ) denervation and subsequent re-innervation. Functionally, the skeletal muscle follows a similar pattern as neural recovery, with immediate loss of force production that steadily improves in parallel with rates of re-innervation. On the other hand, traumatic injury to the muscle itself, specifically volumetric muscle loss (VML), results in an irrecoverable loss of muscle function. Recent work has indicated significant impairments to the NMJ following this injury that appear chronic in nature, alongside the lack of functional recovery. Thus, the goal of this study was to compare the effects of nerve and muscle injury on NMJ remodeling. Even numbers of adult male and female mice were used with three experimental groups: injury Naïve, nerve crush, and VML injury; and three terminal timepoints: 3-, 48-, and 112-days post-injury. Confirming the assumed recoverability of the two injury models, we found in vivo maximal torque was fully restored following nerve-crush injury but remained at a significant deficit following VML. Compared to injury Naïve and nerve-crush injury, we found VML results in aberrantly high trophic signaling (e.g., neuregulin-1) and numbers of supporting cells, including terminal Schwann cells and sub-synaptic nuclei. In some cases, sex differences were detected, including higher rates of innervation in females than males. Both nerve crush and VML injury display chronic changes to NMJ morphology, such as increased fragmentation and nerve sprouting, highlighting the potential of VML for modeling NMJ regeneration in adulthood, alongside the established nerve-injury models.

Cranio-Spinal Irradiation in low-middle income setting: A dosimetric comparison and literature review.

INTRODUCTION: Volumetric modulated arc therapy (VMAT) is a relatively new treatment technique in the middle-east and north African region. More so, is its application for cranio-spinal irradiation (CSI). We report the experience of this implementation in Tunisia, by comparing dosimetric outcomes between VMAT and Three-Dimensional Conformal Radiotherapy (3DCRT) and evaluating their efficiency in terms of treatment delivery time. METHODS: We conducted an in-silico dosimetric study, on 29 patients treated with CSI. Patients treated with 3DCRT were replanned in VMAT and vice-versa. Doses to target volumes (TV) and organs at risk (OAR) were collected from the Treatment Planning System (TPS). Recorded treatment time was extracted from the TPS and beam-on-times were calculated. RESULTS: VMAT provided higher TV coverage for CSI PTV (V95 % = 97.4 % vs 93.4 %, p < 0.001) and for boost PTV (96.3 % vs 93.4 %, p = 0.005). VMAT demonstrated better conformity (0.97 vs 0.93) and homogeneity (0.1 vs 0.26) indexes (p < 0.001). Both techniques met constraints for OAR, but neither achieved recommended limits for the skin, lens, or pituitary gland. VMAT showed lower maximum doses for the majority of OAR and achieved lower mean doses to the cochlea, parotids, heart, oesophagus, pancreas and bladder. However, it resulted in higher low doses to non-target tissue (V5Gy = 45.6 % vs 27.5 %, p < 0.001). Recorded treatment time was longer with VMAT compared to 3DCRT (1387 vs 683 s; p < 0.001), as well as the beam-on-time (453 and 162 s, p < 0.001). CONCLUSION: VMAT offered improved TV coverage, conformity, and homogeneity. It protected some OAR better. This came at the expense of higher low-dose exposure to non-target tissue. Treatment times were longer with VMAT. IMPLICATIONS FOR PRACTICE: Our study suggests the feasibility of implementing VMAT for CSI in low-middle-income countries. Follow-up is required to study the clinical translation of the dosimetric outcomes of VMAT.

Digital Twin for Volumetric Thermal Error Compensation of Large Machine Tools.

Machine tool accuracy is greatly influenced by geometric and thermal errors that cause positioning deviations within its working volume. Conventionally, these two error sources are treated separately, with distinct procedures employed for their characterization and correction. This research proposes a unified volumetric error compensation approach in terms of a calibration procedure and error compensation model, which considers geometric and thermal errors as a single error source that exhibits temporal variation primarily due to changes in the machine's thermal state. Building upon previous works that introduced a fully automated volumetric calibration procedure capable of characterizing the variation in volumetric error over time, this study extends this methodology, incorporating multiple temperature sensors distributed throughout the machine and generating a digital twin based on a volumetric error compensation model capable of predicting and compensating for the volumetric error over time at any point in the workspace, using temperature measurements and axis positions as inputs. This methodology is applied to a medium-sized milling machine tool. The digital twin is trained and validated on volumetric calibration tests, wherein various controlled heat sources are employed to induce thermal variations while measuring the temperatures in the machine.

Volumetric analysis of maxillary sinuses for gender determination: Manual vs.3D segmentation.

The effectiveness of manual calculations versus 3D segmentation techniques in volumetric analysis of maxillary sinuses for gender determination is of interest. Maxillary sinuses, which vary anatomically due to factors like age, ethnicity, and gender, are crucial in forensic and anthropological contexts. Traditional methods, relying on two-dimensional imaging, are often time-consuming and prone to errors, whereas 3D segmentation offers a more precise and efficient approach. This research evaluates both methods in terms of reliability, accuracy, and practical use, potentially influencing their application in clinical and forensic settings. The findings may also enhance understanding of anatomical variations in maxillary sinuses across populations, contributing to more accurate gender determination.

Evaluation of the prognostic effectiveness of liver metastasis volume by volumetric measurement in colorectal cancer.

Aim: To evaluate the relationship between liver metastasis volume and survival in colorectal cancer patients using the volumetric measurement method.Methods: 114 colorectal cancer patients with isolated liver metastases were included in the study. Liver tumor volume, total liver volume were calculated from the patients images at the time of diagnosis. Vitrea 7.14 imaging software was used for liver volume analysis and volume analysis of each metastasis.Results: Median overall survival(OS) in the group with tumor volume <42 ml3 was 30.98 months In the group with tumor volume ≥42 ml3, median OS was 16.36 months (p: 0.001). In patients who underwent metastasectomy, the median OS in the group with a tumor volume <42 ml3 was 52.3 months, the median OS in the group with a tumor volume ≥42 ml3 was 22.2 months. In patients who did not undergo metastasectomy, the median OS in the <42 ml3 group was 20.23 months, the median OS in the ≥42 ml3 group was 15.63 months.Conclusion: In our study, we found that liver metastasis volume was prognostic for OS. It is argued that tumor volume measurement by volumetric measurement is a widely used method in the decision for metastasectomy in liver metastatic colorectal cancer patients.

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Correlation between osteoporosis and endplate damage in degenerative disc disease patients: a study based on phantom-less quantitative computed tomography and total endplate scores.

BACKGROUND: Osteoporosis and degenerative disc disease (DDD) are prevalent in the elderly population. Damage to the vertebral endplate, which impairs nutrient supply to the disc, serves as both a significant initiator and a hallmark of DDD. This study was aimed to explore the association between osteoporosis and endplate damage. METHODS: This retrospective study included 205 patients with DDD who were treated at tianjin hospital from January 2019 to May 2023. We collected data on age, sex, body mass index (BMI), phantom-less quantitative computed tomography (PL-QCT) values, and total endplate scores (TEPS). The average PL-QCT value of L1-L4 and TEPS were used to represent volumetric bone mineral density (v-BMD) and the degree of endplate damage, respectively. Based on the average PL-QCT value of L1 and L2, patients were divided into three groups: normal group (BMD > 120 mg/cm3), osteopenic group (80 mg/cm3 ≤ BMD ≤ 120 mg/cm3), and osteoporosis group (BMD < 80 mg/cm3). Multiple linear regression models were used to identify independent factors associated with endplate damage. RESULTS: The overall TEPS (4.3±1.3 vs 5.0±1.0 vs 5.9±1.5, p<0.01) and segment (L1/2-L4/5) TEPS (p<0.05) in each group showed significant difference (R=-0.5), increasing in order from normal group to osteoporosis group. A significant negative correlation was found between TEPS and PL-QCT values in overall and each segments (p<0.001). The PL-QCT values and age (p<0.05) were independent factors influencing endplate damage. There were significant differences in the average number of TEPS ≥7 segments per patient among the three groups, with 1.16, 0.41, and 0.2 segments/person from osteoporosis group to normal group. CONCLUSIONS: Our study showed a significant positive correlation between osteoporosis and endplate damage. Attention is warranted for patients with osteopenia to prevent progression to osteoporosis, potentially leading to exacerbated DDD. The management of patients with both DDD and osteoporosis necessitates comprehensive treatment strategies that address both the BMD and endplate aspects of these conditions.

The Effects of Metakaolin on the Properties of Magnesium Sulphoaluminate Cement.

Magnesium sulphoaluminate (MSA) cement has good bonding properties and is suitable as an inorganic adhesive for repairing materials in civil engineering. However, there are still some problems with its use, such as its insufficient 1 day (d) strength and poor volumetric stability. This paper aims to investigate the influences of metakaolin (MK) on the physical and mechanical properties of magnesium sulphoaluminate (MSA) cement. The hydration products and microstructures of typical MSA cement samples were also analysed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The results showed that the addition of metakaolin reduces the fluidity and shortens the setting time of the MSA cement. The initial setting time and final setting time shortened maximally by 15-27 min and 25-48 min, respectively, with the addition of 10-30% metakaolin. Moreover, the compressive strength and flexural strength of the MSA cement improved significantly with the addition of 10-30% metakaolin at a curing age of 1 d. Compared with the compressive and flexural strengths of the control sample at 1 d, the compressive strengths of the modified samples showed obvious increases of 98%, 101%, and 109%, and the flexural strengths increased by 39%, 31%, and 26%, respectively, although they decreased slightly when the curing ages were 7 d, 14 d, and 28 d. The addition of 10% metakaolin improved the water resistance of the MSA cement immersed in water for 7 d and resulted in even higher water resistance at 28 d. The addition of 10-30% metakaolin improved the volumetric stability of the MSA cement with increasing dosages before 28 d of ageing. XRD and SEM-EDS analyses showed that the metakaolin accelerated the early hydration reaction and optimised the phase composition of the MSA cement. The results indicate that the addition of 10-20% metakaolin improved the strength after 1 d of ageing, water resistance, and volumetric stability of the MSA cement, providing theoretical support for the application of MAS cement as an inorganic bonding agent for repairing materials.

Evaluating the Effectiveness of Proton Beam Therapy Compared to Conventional Radiotherapy in Non-Metastatic Rectal Cancer: A Systematic Review of Clinical Outcomes.

Background and Objectives: Conventional radiotherapies used in the current management of rectal cancer commonly cause iatrogenic radiotoxicity. Proton beam therapy has emerged as an alternative to conventional radiotherapy with the aim of improving tumour control and reducing off-set radiation exposure to surrounding tissue. However, the real-world treatment and oncological outcomes associated with the use of proton beam therapy in rectal cancer remain poorly characterised. This systematic review seeks to evaluate the radiation dosages and safety of proton beam therapy compared to conventional radiotherapy in patients with non-metastatic rectal cancer. Materials and Methods: A computer-assisted search was performed on the Medline, Embase and Cochrane Central databases. Studies that evaluated the adverse effects and oncological outcomes of proton beam therapy and conventional radiotherapy in adult patients with non-metastatic rectal cancer were included. Results: Eight studies were included in this review. There was insufficient evidence to determine the adverse treatment outcomes of proton beam therapy versus conventional radiotherapy. No current studies assessed radiotoxicities nor oncological outcomes. Pooled dosimetric comparisons between proton beam therapy and various conventional radiotherapies were associated with reduced radiation exposure to the pelvis, bowel and bladder. Conclusions: This systematic review demonstrates a significant paucity of evidence in the current literature surrounding adverse effects and oncological outcomes related to proton beam therapy compared to conventional radiotherapy for non-metastatic rectal cancer. Pooled analyses of dosimetric studies highlight greater predicted radiation-sparing effects with proton beam therapy in this setting. This evidence, however, is based on evidence at a moderate risk of bias and clinical heterogeneity. Overall, more robust, prospective clinical trials are required.

Similar Pathophysiological Mechanisms Between Osteoarthritis and Vascular Disease.

Osteoarthritis (OA) is a prevalent, chronic joint disorder affecting millions of people worldwide, characterized by articular cartilage degradation, subchondral bone remodeling, synovial cytokine secretion, and osteophyte formation. OA primarily affects the hips, knees, hands, and spine. Patients with OA exhibit a higher prevalence of cardiovascular comorbidities and potentially important associations between OA and cardiovascular diseases have prompted investigations into potentially similar pathophysiological associations. This review explores the coexistence of atherosclerotic peripheral vascular disease (ASPVD) in OA patients, including evidence from a contemporary study suggesting associations between OA and arterial wall thickness and blood flow changes which are characteristic of early atherosclerosis, and which stimulate reactive pathology in endothelial cells. Observations from this study demonstrate elevated arterial flow volume and increased intima-media thickness in arteries ipsilateral to OA knees, suggesting a potential link between OA and arterial wall disease. We further explore the intricate relationship between the vascular system and skeletal health, highlighting bidirectional interactions among endothelial cells, inflammatory cells, and various bone cells. Mechanical endothelial cell dysfunction is discussed, emphasizing the impact of vessel wall material changes and endothelial cell responses to alterations in fluid shear stress. Inflammatory changes in OA and ASPVD are also explored, showcasing shared pathophysiological processes involving immune cell infiltration and pro-inflammatory cytokines. Additionally, the role of hypofibrinolysis in OA and ASPVD is discussed, highlighting similarities in elevations of the hypercoagulative and hypofibrinolytic factor, plasminogen activator inhibitor (PAI-1). The review suggests a provocative relationship among low-grade chronic inflammation, endothelial dysfunction, and hypofibrinolytic states in OA and ASPVD, warranting further investigation. In conclusion, this review provides an exploration of the possible associations between OA and ASPVD. While the ongoing study's findings and other reports are observational, they suggest shared pathophysiological processes and emphasize the need for further research to elucidate additional potentially correlative linkages between these conditions. Understanding common molecular pathways may pave a way for targeted interventions that address both OA and ASPVD.

Quantitative evaluation of Scout Accelerated Motion Estimation and Reduction (SAMER) MPRAGE for morphometric analysis of brain tissue in patients undergoing evaluation for memory loss.

BACKGROUND: Three-dimensional (3D) T1-weighted MRI sequences such as the magnetization prepared rapid gradient echo (MPRAGE) sequence are important for assessing regional cortical atrophy in the clinical evaluation of dementia but have long acquisition times and are prone to motion artifact. The recently developed Scout Accelerated Motion Estimation and Reduction (SAMER) retrospective motion correction method addresses motion artifact within clinically-acceptable computation times and has been validated through qualitative evaluation in inpatient and emergency settings. METHODS: We evaluated the quantitative accuracy of morphometric analysis of SAMER motion-corrected compared to non-motion-corrected MPRAGE images by estimating cortical volume and thickness across neuroanatomical regions in two subject groups: (1) healthy volunteers and (2) patients undergoing evaluation for dementia. In part (1), we used a set of 108 MPRAGE reconstructed images derived from 12 healthy volunteers to systematically assess the effectiveness of SAMER in correcting varying degrees of motion corruption, ranging from mild to severe. In part (2), 29 patients who were scheduled for brain MRI with memory loss protocol and had motion corruption on their clinical MPRAGE scans were prospectively enrolled. RESULTS: In part (1), SAMER resulted in effective correction of motion-induced cortical volume and thickness reductions. We observed systematic increases in the estimated cortical volume and thickness across all neuroanatomical regions and a relative reduction in percent error values compared to reference standard scans of up to 66 % for the cerebral white matter volume. In part (2), SAMER resulted in statistically significant volume increases across anatomical regions, with the most pronounced increases seen in the parietal and temporal lobes, and general reductions in percent error relative to reference standard clinical scans. CONCLUSION: SAMER improves the accuracy of morphometry through systematic increases and recovery of the estimated cortical volume and cortical thickness following motion correction, which may affect the evaluation of regional cortical atrophy in patients undergoing evaluation for dementia.

Effects of electron density force to 1.0 and fill to 1.0 on VMAT treatment plans for lung SBRT.

PURPOSE: The aim of this study is to determine the effect of forcing and filling the electron density (ED) to 1.0 of the planning target volume (PTV) overdose distribution in lung SBRT treatment leading to shortening patient treatment time and increasing patient comfort by reducing MU/fraction due to ED manipulation effect. METHODS: In this study, 36 lung SBRT plans of 12 suitable patients who prescribed a total dose of 50 Gy in five fractions were generated with Monaco v.5.10 TPS using the Monte Carlo (MC) algorithm and volumetric modulated arc therapy (VMAT) technique by PTV ED values forcing as well as filling to 1.0 and comparatively assessed. The first group of plans was created by using the patient's original ED, second and third groups of plans were reoptimized by forcing and filling the ED of PTV to 1.0, respectively, therefore acquiring a new dose distribution which lead to comparatively assessment the effects of changes in ED on PTV and OAR doses. RESULTS: Assessment of treatment plans revealed that mean MU/fx numbers were decreased by 76% and 75.25% between Groups 1 and 2, Groups 1 and 3, respectively. The number of segments was also reduced in Group 1 by up to 15% compared with Groups 2 and 3. Maximum HI and CI differences for PTV between Groups 1 and 2 were less than 1% and Groups 1 and 3 were 1.5% which indicates all 3 group plans were comparable in terms of dose distribution within PTV. CONCLUSIONS: Forcing and filling the ED of PTV to 1.0 strategy has provided reduced a number of segments and MU/fx without a significant change in PTV mean and maximum doses, thereby decreasing treatment time and patient discomfort during treatment. This process should be considered in line of a potential number of patients as well as prescribed dose and MU/fx numbers.